The present invention relates to machine for packaging in a non-germ atmosphere which is distinguished by a container sterilization means and a filling and packing means in a non-germ atmosphere.
A method of filling the sterilized food in a sterilized container in a non-germ atmosphere is considered better than a method of filling the food in an cleaned atmosphere which still contains germs for the following reasons.
(1) Food is sterilized with high temperature in a very short time, so that the quality of the food remains good for a long time.
(2) Since food is sterilized and contains no germs, it can be kept at normal temperature.
(3) Keeping food cold is unnecessary, so that energy otherwise needed for cooling the food can be saved.
(4) Food can be filled in a bigger container than a can for canned food, so that it is economical.
(5) Food can be saved in a warehouse and on a shelf for a long time, so that production of the food can well be planned.
(6) Since the containers are sterilized before food is filled, they do not have to be heat-proof as compared to the heat required for canned food and retort food.
For the reasons described above, the method of filling the sterilized food in a sterilized container in a non-germ atmosphere is widely applied for filling many kind of foods.
The prior art of this method is largely separated into two sections, a container sterilization section and a filling and packing section. In the former section, containers are sterilized as they are carried through a sterilization atmosphere. In the latter section, food is filled in the sterilized containers and the containers are sealed with sterilized lids as the containers are carried to each position in a non-germ atmosphere, a food filling position, a lid providing position and a lid sealing position.
One prior art disclosure of machine for packaging in a non-germ atmosphere is described in Japanese Patent Provisional Publication No. 55-163134 wherein food is filled after containers are sterilized and dried while they are carried by a conveyer. Another prior art disclosure is Japanese Patent Provisional Publication No. 62-287833 which describes a method such that each container, which is airtightly segregated from others, is carried and it is sterilized, dried and filled with food.
The above-mentioned two prior art references, however, can be applied only to uniformly sized containers. To apply them to a different sized container, the conveyer has to be replaced. Although in the latter prior art, the machine described is one that can be adjustable to a different sized container, it has the problem that an atmosphere wherein containers are sterilized and dried and an atmosphere wherein food is filled in the containers cannot be airtightly divided. Also in this prior art reference, washing the lid sealing means, the sterilization of the containers and maintenance work of the machine are disturbed by a carrying means. Further, positioning the containers for sealing is rather difficult, so that sealing is often done improperly.
In the prior art of machines for packaging in a non-germ atmosphere, the machines are arranged so that containers are carried with intermittent stopping at a position such as a food filling position and a lid sealing position. A typical intermittent carrying means applied in a fill-and-pack in a non-germ atmosphere machine is described in Japanese Patent Provisional Publication No. 59-115220. In this means, holder plates are secured at regular intervals to the endless chain which rotates in the non-germ chamber, a container holder is secured to each holder plate, and a container is hung at the flange by the container holder.
The problem of the prior art is that the machine is only applicable for uniformly sized containers so that when it is applied to a different sized container, the container holders have to be replaced.
Replacing the holders takes a lot of time and requires hard work. It further disrupts the non-germ atmosphere. Recreating a non-germ atmosphere also takes time and requires extra work.
The first object of the present invention therefore is to provide a machine that can be applied to different sized containers without replacing any elements or without disrupting a non-germ atmosphere.
In a machine for packaging in a non-germ atmosphere, preventing a sterilization agent from staying in a container and from leaking in the non-germ atmosphere is essential to keep the food good for a long time.
Japanese Patent Provisional Publication describes a prior art wherein a room for sterilizing containers is segregated from the room for filling food and sealing lids, and through a opening mouth, which connects both rooms, the sterilized containers are carried from the former room to the latter room. The pressure in the room for filling food and sealing lids is arranged higher than the room for sterilizing containers, so that a sterilization agent is prevented from leaking in the room for filling food and sealing lids.
The problem of this prior art is that the sterilized containers cannot completely be dried, so that some of the sterilization agent would remain on the surface of the containers.
The containers are sterilized in such a manner that a liquidized sterilization agent is atomized and is sprayed to the containers. Then by blowing hot wind on the containers, the sterilization agent on the surface of the containers is evaporated. However, since the sterilization agent is atomized and is floating in the container sterilization room, even though the sterilization agent remained on the surface of the containers is blown away, the remaining atomized sterilization agent in the room would stick to the containers.
Another problem of the prior art is that it is often difficult to evenly spray the atomized sterilization agent on the containers, so that some portions of the containers would remain unsterilized.
The second object of the present invention therefore is to control the air flow in the container sterilization room, so that the atomized sterilization agent is prevented from spreading too broadly so that the whole surface of the containers can perfectly be sterilized.